Relationship between mesiodistal width of four maxillary incisors and inner canthal distance

Estimating the width of maxillary incisors may be difficult when artificial teeth are selected for edentulous patients. This study examined the relationship between mesiodistal width of four maxillary incisors (WFMI) and inner canthal distance (ICD). Methods & Materials: In this descriptive study, 100 subjects (50 male and 50 female mean age 22.87 years) without facial and dental deformities were selected in this cross sectional study. WFMI and ICD were measured with Boley gauge. A mathematic formula to evaluate correlation between WFMI and ICD in 15 subjects has been used. (y = 1/784x-0/023x2) (y: mesiodistal width of four maxillary incisors, x: inner canthal distance). Then the difference between calculated size and real size of teeth was compared with paired t test. The mean of WFMI was 32.95±1.47mm and the mean of ICD was 31.9±1.83mm. In 70% of subjects, the difference between WFMI and ICD was less than 2mm. The correlation was r=0.345 (P=0). The calculated "model" for this relationship was y=1.784x – 0.023x2 (y: mesiodistal width of four maxillary incisors, x: inner canthal distance). 1- ICD is a good landmark for estimating WFMI. 2- The calculated model is competent and useful.